PART I
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TITLE: Microbicides and mucosal vaccines for HIV, Hepatitis B, Herpes
Simplex - illusion or reality
SOURCE: Checkbiotech, Switzerland, by Silke Luetzelschab
http://www.checkbiotech.org/root/index.cfm?
fuseaction=newsletter&topic_id=1&subtopic_id=2&doc_id=11588
DATE: 7 Nov 2005
------------------ archive: http://www.genet-info.org/ ------------------
Microbicides and mucosal vaccines for HIV, Hepatitis B, Herpes Simplex -
illusion or reality
Researchers from the USA discussed the crucial importance and challenges
of plant-derived microbicides and mucosal vaccines to prevent
transmission of sexually transmitted diseases as HIV, Hepatitis B, Herpes
Simplex and others.
In a recent publication in the journal Vaccine, a team of researchers
wrote, "With the annual incidence of sexually transmitted infections
(STIs) at epidemic levels worldwide, there is clear need for more
effective methods of preventing transmission of prevalent pathogens".
Translated into numbers, sexually transmitted and reproductive diseases
account for about one-third of diseases among women of reproductive age
and about one-fifth among the entire population.
Due to these staggering statistics, there is a lot of ongoing research to
develop microbicides and mucosal vaccines against STIs. Most vaccines
work by controlling or eliminating the infection, whereas mucosal
vaccines prevent the transmission of the disease at the mucosal surface.
Microbicides and vaccines against HIV are already being evaluated in
clinical trials at international sites. So far all vaccines on the market
are derived by conventional methods. But the idea of vaccine and
microbicide production in transgenic plants is gaining more and more
interest. The advantages compared to conventional methods are lower cost,
larger scale, and perhaps speed to production.
That is why the work of Dr. Kevin J. Whaley and Mapp Biopharmaceutical
Inc. in San Diego, USA is so important. Mapp Biopharmaceuticals Inc. is
collaborating with the Biodesign Institute at Arizona State University,
USA and the University of Maryland at Baltimore Vaccine Center on the
development of plant-derived microbicides and mucosal vaccines to four
crucial STIs: HIV, Hepatitis B Virus, Herpes Simplex Virus and Human
Papilloma Virus.
Looking at the high prices of vaccines for sexual and reproductive
health, Dr. Whaley has a justifiable concern about their availability to
the general public, especially in developing countries. The researchers
envision lower costs for plant derived vaccines, although Dr. Whaley told
Checkbiotech that this cannot be confirmed until a plant-derived product
is on the market.
Mucosal delivery of a vaccine means that there is no need for disposal of
syringes and needles, which is often a burden in the delivery of
vaccines, especially in developing countries. Dr. Whaley sees as suitable
dosing forms vaginal tablets or combined application with gel microbicides.
Dr. Whaley stated in their paper that it has been difficult to achieve
high concentrations of mucosal antibodies with mucosal application of a
plant-derived vaccine. "So this still remains a challenge," he told
Checkbiotech. If this impediment could be overcome, vaccines derived by
molecular farming may offer the additional advantage of multi-agent
products, preventing transmission of several STIs at once.
In Dr. Whaley's opinion, another important point is the significantly
higher specificity of biopharmaceuticals, compared to conventional
vaccines or microbicides. "This may enhance safety and efficacy," he
concludes.
"To address environmental concerns, manufacturing of plant-derived
microbicides and mucosal vaccines can take place in enclosed facilities,"
Dr. Whaley further explained. But to reach the point of
commercialisation, a lot remains to be done: manufacturing procedures
according to cGMP (Good Manufacturing Practice) need to be elaborated,
clinical trials for safety and efficacy have to be planned and carried
out according to GCP (Good Clinical Practice) and finally the regulatory
authorities have to give their stamp of approval.
Although there is still a long way to go until plant-derived mucosal
vaccines or microbicides may be available. Mapp Biopharmaceutical Inc.
has been contributing, with past and present collaborators, and is hoping
to do so in the future as well.
Silke Luetzelschwab is a Molecular Biologist and a Scientific Writer for
Checkbiotech.
Kevin J. Whaley et al.
Preventing transmission: plant-derived microbicides and mucosal vaccines
for reproductive tract. Vaccine, 23 (2005), p. 1819-1822
Dr. Kevin Whaley
Mapp Biopharmaceutical Inc.
6160 Lusk Blvd.
Suite C105
San Diego, CA
92121
United States
e-mail: kwhaley@mapp-biopharmaceutical.com
Tel: +1 800 372 21 76
Website: www.mapp-biopharmaceutical.com
PART II
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TITLE: Edible vaccines 'to replace jabs'
SOURCE: British Broadcasting Corporation
http://news.bbc.co.uk/go/pr/fr/-/1/hi/health/4393854.stm
DATE: 6 Nov 2005
------------------ archive: http://www.genet-info.org/ ------------------
Edible vaccines 'to replace jabs'
An edible allergy vaccine could one day replace injections, a study says.
Jabs, which build up antibodies are used to treat severe forms of hay-
fever and cat and venom allergies, but can sometimes trigger dangerous
reactions.
The Japanese researchers said the rice-based vaccine they tested on mice
is less dangerous and more simple.
They wrote in the journal Proceedings Of The National Academy of Sciences
that it "opens new possibilities" for allergy treatment in the future.
One in four people are estimated to suffer from allergies, ranging from
reactions to food to respiratory and skin allergies.
Most can be controlled by regulating diet and the immediate environment -
or drugs can be taken to limit the symptoms.
But for severe hay-fever and cat allergies, as well as for people with
particularly bad reactions to bee and wasp stings, courses of anti-
allergy injections can be given.
These can take a couple of years to complete and have to be done in
hospital because of the danger of the allergens given in the jabs
prompting an anaphylactic reaction - injections all but stopped for a
while in the UK in the 1980s because of a number of deaths.
The vaccine developed by the joint University of Tokyo and Shimane
University team uses genetically-modified rice to build up the immune system.
Risk
The oral vaccine contains only part of the allergen in comparison to
traditional injections and therefore carry less risk of a bad reaction,
the study said.
In the tests on mice allergic to cedar pollen, those taking the rice
vaccine for four weeks showed fewer allergic responses and sneezed less.
Report co-author Hidenori Takagi said the findings "open new
possibilities" for the treatment of allergies.
And he added: "Plant-based vaccines have several potential advantages
over traditional whole-allergen injected vaccines since they are simpler
to administer and cheaper to produce."
But he said more research was needed before a human vaccine could be produced.
Muriel Simmons, chief executive of Allergy UK, said more research was
needed into treating allergies.
"Courses of injections have to be tightly monitored in hospital so
anything that offers the hope of an easier and safer way to give them is
to be welcomed."
--
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